When a dog wags its tail, we usually interpret it as a sign of joy and happiness. However, a group of scientists from the University of Trento (Italy) has discovered that the swaying of your appendix is also a sign of sadness and that the difference lies in the side towards which the movement leans , the right being a sign of positive emotion and the left negative.
To obtain this conclusion, the experts studied the reaction of different dogs to the visualization of recordings of other dogs wagging their tails. This bias in the tail swing is difficult to appreciate for the human eye, but not for the canine, since they detect it easily. The results revealed that the dogs suffered an increase in their heart rate and anxiety when seeing another dog with the tail slightly tilted to the left , as they attributed it to negative sensations such as being in danger or threat. Instead, when the dog in the video tipped its tail to the right, its namesake remained totally relaxed.
According to the study, it is a type of unintended communication, derived from the asymmetric functioning of the dog's brain. Thus, the tail would lean towards the side of the currently active cerebral hemisphere.
